It uses a chain - under normal operating conditions, does not need servicing - ie. should last the life of the engine. Because it is a chain make sure that the car follows a regular oil change interval with the appropriate viscosity of oil. Chains tend to be a bit tougher on the engine oil.
2002 Corolla S, Silverstream, 1.8L 1ZZ-FE (VVT-i)
2003 Matrix XRS, Cosmic Blue, 1.8L 2ZZ-GE (VVTL-i)